Ball screw device, machine component manufacturing method, machine manufacturing method, vehicle manufacturing method, machine component, machine, vehicle, hydraulic forming method, and hydraulic forming die

Abstract

A ball screw device includes a nut (3), a screw shaft, and a plurality of balls arranged between the nut (3) and the screw shaft. The nut (3) includes a first member (11) disposed to surround the screw shaft, a second member (10) disposed between the screw shaft and the first member (11), and a third member (12) disposed between the first member (11) and the second member (10). The third member (12) includes a laminate body (12A) having a plurality of plates (22a, 22b) laminated in an axial direction. The laminate body (12A) includes an inner surface facing an outer surface of the second member (10). The inner surface of the laminate body (12A) has a shape corresponding to a shape of the outer surface of the second member (10).

1 . A ball screw device comprising:
 a nut;   a screw shaft; and   a plurality of balls arranged between the nut and the screw shaft,   wherein the nut includes a first member disposed to surround the screw shaft, a second member disposed between the screw shaft and the first member, and a third member disposed between the first member and the second member,   wherein the third member includes a laminate body having a plurality of plates laminated in an axial direction,   wherein the laminate body includes an inner surface facing an outer surface of the second member, and   wherein the inner surface of the laminate body has a shape corresponding to a shape of the outer surface of the second member.   
     
     
         2 . The ball screw device according to  claim 1 ,
 wherein the outer surface of the second member has a convex shape, and   wherein the inner surface of the laminate body has a concave shape substantially matching the convex shape of the second member.   
     
     
         3 . The ball screw device according to  claim 1 ,
 wherein the plurality of plates of the laminate body include a plurality of annular plates, and   wherein the plurality of annular plates are formed such that peripheral shapes of inner peripheral surfaces are substantially the same as each other and/or the peripheral shapes of the inner peripheral surfaces are different from each other.   
     
     
         4 . The ball screw device according to  claim 1 ,
 wherein the plurality of plates of the laminate body include phase matching portions each provided at a specific position in a circumferential direction.   
     
     
         5 . The ball screw device according to  claim 1 ,
 wherein a material of the third member is different from a material of the second member.   
     
     
         6 . The ball screw device according to  claim 1 ,
 wherein the inner surface of the laminate body includes a plurality of steps based on a difference in inner surface height of two adjacent plates.   
     
     
         7 . The ball screw device according to  claim 1 ,
 wherein the plurality of plates of the third member include a first plate and a second plate having a thickness different from that of the first plate.   
     
     
         8 . A machine comprising:
 the ball screw device according to  claim 1 .   
     
     
         9 . A vehicle comprising:
 the ball screw device according to  claim 1 .   
     
     
         10 . A hydraulic forming die comprising:
 a tubular laminate body having a plurality of plates laminated in an axial direction,   wherein the laminate body includes an inner peripheral surface for a forming.